Levo is an API Observability and Security testing platform. Levo discovers, documents, inspects and tests your APIs continuously as early as possible in the SDLC. Levo is the DevSecOps platform for your applications. #apis #devsecops #shiftleft #apimanagement #apilifecycle

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Scientific American Supplement, No. 392, July 7, 1883 by Various, is part of the HackerNoon Books Series. You can jump to any chapter in this book . THE PRODUCTION OF FIRE. here THE PRODUCTION OF FIRE. In 1867 the Abbé Bourgeois found at Thenay, near Pont-levoy (Loir-et-Cher), in a marly bank belonging to the most ancient part of the middle Tertiary formation, fragments of silex which bore traces of the action of fire. This fire had not been lighted by accidental causes, for, says Mr. DeMortillet ( , p. 90), the causes of instantaneous conflagrations can be only volcanic fires, fermentations, and lightning. "Now, in the entire region there is no trace of volcanic action, and neither are there any traces of turfy or vegetable deposits capable of giving rise to spontaneous inflammations--phenomena that are always very rare and very exceptional, as are also conflagrations started by lightning. Well, in the Thenay marls, the pieces of silex that had undergone the action of fire were found disseminated at different levels, and this could not have been a simple accident, but was evidently something that had been done intentionally. There existed, then, during the Aquitanian epoch, a being who was acquainted with fire and knew how to produce it." Le Prehistorique Mr. De Mortillet supposes that this being was an animal intermediate between man and the monkey, which he calls the . anthropopithecus This precursor of man made use of fire for splitting silex and manufacturing from it instruments whose cutting edge he perfected by means of a series of retouchings produced by slight percussions upon one of the surfaces only. I shall not enter in this place upon a discussion as to the existence of an anthropopithecus or Tertiary man, whom every one does not as yet accept, but will confine myself to giving the facts as to the use of fire in the remotest epochs, incontestable proofs of which exist from the time at which Quaternary man made his appearance. How this was discovered is indicated, according to Aryan tradition, by the Vedic hymns. The ancestors of the Aryans, these tell us, had seen the lighting dart forth from the shock of black clouds. They had seen the spark that fired the forests issue from the friction of dry branches agitated by the storm. They took a branch of soft wood, , and passing a thong around a branch of hard wood, , they caused it to revolve rapidly in a cavity in the , and thus evoked the god , whom they nourished with libations of clarified butter, . arani pramontha arani Agni soma The , became the of the Greeks, the Titan who stole the fire, and it is from the Sanscrit that is derived the Latin , "fire," and the Greek Αγνος, "pure," and the of the Christians, who purifies all. Pramontha Prometheus Agni Ignis Agnus Dei Orientalists generally agree that the sign which is seen under the forms , , or , on a large number of objects of Aryan origin is a sort of sacred hieroglyphic, representing the or , formed of two pieces of soft wood fixed by four pins in such a way as not to revolve under the pressure of the Pramontha. arani svastika This process of producing fire is also found among a host of more or less savage peoples, and especially in India, where, during the last month of the great feast of sacrifices, the sacred fire must always be kindled three hundred and sixty times a day with nine different kinds of wood that are prescribed by the rite. Fig. 1 shows the arrangement in use among the Eskimos, and Fig. 2 that employed by the Indians of North America. In 1828 there still existed at Essen, in Hanover, an analogous apparatus designed to produce an alarm fire. This was a large, horizontal, round wooden bar whose extremities pivoted in two apertures formed in vertical posts, and which was provided with a cord that was wound around it several times. Several persons, by pulling on the ends of this cord, caused the bar to revolve alternately in one direction and the other, and the heat developed by the friction lighted some tow that had previously been inserted in one of the apertures in the post. It is certain that the alternate motion must have been produced directly by hand before being effected by cords. This simpler process is still in use in Tasmania, Australia, Polynesia, Kamtschatka, Thibet, Mexico, and among the Guanches of the Canary Isles, who are supposed to be the last representatives of the inhabitants of Atlantis, which sank under the waters at the close of the Quaternary epoch. Chamisso, who accompanied Kotzebue in his voyage, describes it as follows: "In the Caroline Islands, they rest a vertical piece of roundish wood, terminating in a point, and about a foot and a half in length and one inch in diameter, upon a second one fixed in the ground, and then give it a rotary motion by acting with the palms of the hands. This motion, which is at first slow and measured, is at length accelerated, while at the same time the pressure becomes stronger, whereupon the dust from the wood which has formed by friction and accumulated around the point of the movable piece begins to carbonize. This dust, which, after a fashion, constitutes a match, soon bursts into flame. The women of Eap are wonderfully dexterous in their use of this process." Fig. 3 shows another manner of obtaining fire by rotation which is employed by the Guachos, a half savage, pastoral people who inhabit the pampas of South America. Longitudinal friction must have preceded that obtained by rotation. It is still in use in most of the islands of Oceanica (Fig. 4), and especially in Tahiti and in the Sandwich Islands. In these latter, says again Chamisso, upon the fixed piece of wood they place another piece of the same kind, about the length of the palm, and press it obliquely at an angle of about 30 degrees. The extremity that touches the fixed piece is blunt, and the other extremity is held with the two hands, the two thumbs downward, in order to allow of a surer pressure. The piece is given an alternating motion, and in such a way that it shall always remain in the same plane inclined at an angle of 30 degrees, and form, through friction, a small groove from six to eight centimeters in length. When the dust thus produced begins to carbonize, the pressure and velocity are increased. Wood of a homogeneous texture, neither too hard nor too soft, is the best for the purpose. The Malays operate as follows: A dry bamboo rod, about a foot in length, is split longitudinally, and the pith which lines the inside is scraped off, pressed, and made into a small ball which is afterward placed in the center of the cavity of one of the halves of the tube. This latter half is then fixed to the ground in such a way that the cavity and ball face downward. The operator next fashions the other half of the tube into a straight cutting instrument like a knife-blade, which he applies transversely to the fixed half and gives an alternating motion so as to produce a sort of sawing. After a certain length of time, a groove, and finally a hole, is produced. The cutting edge of the instrument is then so hot that it sets on fire the ball with which it has come in contact. Some peoples, the Fuegians especially, procure fire by striking together two flints. In the Aleutian Islands these latter, having been previously covered with sulphur, are struck against each other over a small saucer of dry moss dusted with sulphur. The Eskimos employ for this purpose pieces of quartz and iron pyrites. In the Sandwich Islands recourse is had to a process that necessitates much skill. There is arranged in a large dry leaf, rolled into the shape of a funnel, a certain number of flints along with some easily combustible twigs. On attaching the leaf to the end of a rod, and revolving the latter rapidly, it is said that fire is produced. Processes that are based upon the clashing of two flint stones must be much more inconvenient of application than we would be led to suppose. We are, in fact, accustomed to see the flint and steel used, but here the spark is a bit of iron raised to red heat through a mechanical action that has violently detached it from the mass under the form of a small sliver. In the case of two flint stones, the light that is perceived is of an entirely different nature, for it is a phosphorescence which is produced, even by a very slight friction, not only between two pieces of silex, but also between two pieces of quartz, porcelain, or sugar; and that the heat developed is but slight is proved by the fact that the phenomenon may occur under water. Of course, fragments of stones may be raised to a red heat through percussion; but this does not often occur, so for this reason the Fuegians keep up with the greatest care the fires that they have lighted, and it is this very peculiarity that has given their country a characteristic aspect and caused it to be named Terra del Fuego (land of fire). When they change their residence they always carry with them a few lighted embers which rest in their canoes upon a bed of pebbles or ashes. The same thing occurs, moreover, among the Australians and Tasmanians, who employ, as we have just seen, the rotary process. There are women among these peoples whose special mission it is to carry day and night lighted torches or cones made of a substance that burns slowly like punk. When, through accident, the fire happens to get extinguished in a tribe, these people often prefer to undertake a long voyage in order to obtain another light from a neighboring tribe rather than have recourse to a direct production of it. We can understand from what is still taking place in these distant countries why the worship of fire should have existed among our ancestors, and why sacerdotal associations, such as the Brahmins of India, the Guebers of Persia, the Vestals of Rome, the priests of Baal in Chaldea and Phenicia should have been specially instituted for producing and preserving it. Plutarch narrates (Numa, chap. ii.) that when the sacred fire happened to go out, there was employed for relighting it a brass mirror that had the form of a cone generated by the hypothenuse of an isosceles rectangular triangle revolving around one of the sides of the right angle. In a poem upon stones attributed to Orpheus, it is said that the sacred fire was also lighted by a bit of crystal which concentrated the rays of the sun upon the material to be inflamed. This process must have been the one that was most usually employed before fire became common. In fact, a plano-convex crystal lens has been found among the ruins of Nineveh. Aristophanes, in the , puts on the stage a coarse personage named Strepsiades, who points out to Socrates how he must manage so as not to pay his debts: Clouds "Streps.--Hast thou seen among druggists that beautiful transparent stone that they employ for lighting a fire? "Socr.--Thou meanest glass. "Streps.--Yes. "Socr.--Well! what wouldst thou do with it? "Streps.--When the registrar shall have made out his summons against me, I will take the glass, and, placing myself thus in the sun, will cause his writing to melt." As well known, writing was then traced on waxen tablets. Servius (in ., xii., 200) affirms that men of ancient times, instead of lighting fire upon the altar themselves, in their sacrifices, caused it to descend from heaven. He adds, according to Pliny, Titus Livius, and several old Latin historians, that Numa, who was initiated into all the wisdom of Etruria, practiced this art with success, but that Tullius Hostilius, having desired to repeat the evocation, guided only by the books of Numa, did not accomplish all the formalities prescribed by the rite and was struck dead by lightning. Æn Is it not curious that twenty-four centuries afterward, in 1753, the physicist Reichman was killed by lightning in trying to repeat Franklin's experiment? This coincidence, however, is not the only one. Pliny (ii., 53) recounts that lightning was evoked by King Porsenna at the time when a monster named , who was ravaging the country, was directing himself toward the capital, Volsinies. Volta If we return to the Vedas, who had the habit of personifying all phenomena, we shall find that the fire Agni was the son of the carpenter who had manufactured the instrument by which it was produced, and of (magic). He took the name of Akta (anointed, [Greek: christos]) when, nourished by libations of butter, he had acquired his full development. The Persians attributed likewise to Zoroaster the power of causing fire to descend from heaven through magic. Saint Clement of Alexandria ( ., lib. iv.) and Gregory of Tours ( , i., 5) speak of this. However this may be, the marvelous art was lost at an early date, for it was at such a date that priests began to have recourse to tricks that were more or less ingenious for lighting their sacred fireplaces in an apparently supernatural manner.-- . Maya Recog Hist. de Fr. A. De Rochas, in La Nature About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Various (2005). Scientific American Supplement, No. 392, July 7, 1883. Urbana, Illinois: Project Gutenberg. Retrieved https://www.gutenberg.org/cache/epub/8742/pg8742-images.html This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at . www.gutenberg.org https://www.gutenberg.org/policy/license.html

THE PRODUCTION OF FIRE

Inside Earth: The Journey of Conru

Topographical Notes

Testing a Clean Architecture in a Frontend Application - Does It Make Sense?

একটি ফ্রন্টএন্ড অ্যাপ্লিকেশনে একটি পরিষ্কার আর্কিটেকচার পরীক্ষা করা - এটি কি অর্থপূর্ণ?

Testen einer sauberen Architektur in einer Frontend-Anwendung – ist das sinnvoll?

Probar una arquitectura limpia en una aplicación frontend: ¿tiene sentido?

Tester une architecture propre dans une application frontale - Cela a-t-il un sens ?

एक दृश्यपटल अनुप्रयोग में एक स्वच्छ वास्तुकला का परीक्षण - क्या यह समझ में आता है?

フロントエンド アプリケーションでクリーンなアーキテクチャをテストする - 意味があるか?

프런트엔드 애플리케이션에서 클린 아키텍처 테스트 - 말이 되나요?

Testando uma arquitetura limpa em um aplicativo front-end - faz sentido?

Bir Ön Uç Uygulamasında Temiz Bir Mimariyi Test Etmek - Mantıklı mı?

Thử nghiệm một kiến trúc sạch trong một ứng dụng giao diện người dùng - Điều đó có hợp lý không?

在前端应用程序中测试干净的架构 - 它有意义吗？

Metla is a new platform that makes managing crypto way easier for users. It offers an impressive suite of tools and features that make it a go-to solution for anyone seeking to streamline their day-to-day crypto management needs. Vested Interest Disclosure: The author is an independent contributor publishing via our brand-as-author program. Be it through direct compensation, media partnerships, or networking, the author has a vested interest in the company/ies mentioned in this story. HackerNoon has reviewed the report for quality, but the claims herein belong to the author. #DYOR The platform offers a range of features that are designed to support the development and use of blockchain technology. Here are some of the key features: Asset tracking Metla allows tracking of all tokens, NFTs and De-FI asssets and activities. Everything associated with the wallet can be explored through Metla’s interface. Powerful Crypto search In Metla users can search for anything crypto, be it NFTs, tokens, specific transactions or wallet data. Metla’s search is the most powerful crypto search out there. Security The platform offers enterprise-grade security tools to help users keep their assets safe Users can run background security checks on wallets, check check if NFT is a spam or counterfeit, keep their wallet token allowances under control and so much more. 4. NFTs With Metla’s NFT section not only users can see all the NFTs they own and all the associated transactions, but also can mint NFTs and NFT collections without leaving the interface. Another cool feature is NFT galleries - users can showcase the NFT they own on Metla’s short links or even their custom domains! 5. De-Fi activities De-Fi tracking is becoming increasingly important as more people turn to decentralized finance for investment and income-generating opportunities. Metla is a platform that enables users to track their De-Fi activities, including staking, borrowing, and lending etc. 6. User-friendly Interface A user-friendly interface is a crucial component of any successful platform, and Metla recognizes this. Metla has been designed with a simple and intuitive interface, making it easy for users to navigate the platform and manage their crypto assets. Metla's interface has been designed to cater to both experienced cryptocurrency traders and newcomers to the market. The platform's user-friendly interface ensures that users can quickly understand how to use the platform and start trading with minimal hassle. Levon Terteryan, the founder of Zeroqode, is the driving force behind the development of Metla. He’s an individual with a passion for both technology and personal wellness. Terteryan believes that technology should not only make our lives easier but also support our well-being and personal growth. With Metla, he has created a platform that not only simplifies the management of crypto assets but also empowers users to track their financial activity, gain insights into their portfolio, and engage with the growing world of crypto and NFTs. Overall, Metla is an excellent solution for anyone looking to manage their cryptocurrency easily and safely. Its features and user-friendly interface make it a go-to platform for managing crypto assets, while its support for NFT transactions adds to its appeal. With its launch, Metla is set to become a comprehensive solution for crypto enthusiasts looking to streamline their management needs.

Introducing Metla: The Ultimate Cryptocurrency Management Platform

Presentamos Metla: la plataforma de gestión de criptomonedas definitiva

Présentation de Metla : la plateforme de gestion de crypto-monnaie ultime

पेश है मेटला: अल्टीमेट क्रिप्टोक्यूरेंसी मैनेजमेंट प्लेटफॉर्म

Metla の紹介: 究極の暗号通貨管理プラットフォーム

Apresentando o Metla: a melhor plataforma de gerenciamento de criptomoedas

Giới thiệu Metla: Nền tảng quản lý tiền điện tử tối ưu

介绍 Metla：终极加密货币管理平台

THE VALUATION OF SEXUAL LOVE

Melhore a obsevabilidade da sua Stack Elastic, baseado em fatos reais A utilização do Dead Letter Queue ajuda ainda mais na obsevabilidade de dados que não foram entregues para Elasticsearch. Como cheguei até aqui Estava realizando testes com um componente de comunicação com o Logstash e por coincidência solicitei a criação de um Indíce no Elasticsearch com caractere em caixa alta (Teste). E adivinha o que o ElasticSearch me retornou? Could not index event to Elasticsearch. status: 400, action: [“index”, {:_id=>nil, :_index=>” Teste -2020.07.08", :routing=>nil, :_type=>”_doc”}, #<LogStash::Event:0x5ad6965c>] , response: {“index”=>{“_index”=>”Teste-2020.07.08", “_type”=>”_doc”, “_id”=>nil, “status”=>400, “error”=>{“type”=>”invalid_index_name_exception”, “reason”=>”Invalid index name [Teste-2020.07.08], must be lowercase ”, “index_uuid”=>”_na_”, “index”=>”Teste-2020.07.08"}}} ! Isso mesmo, ele não aceitou a criação do indíce e a mensagem não foi entregue. SIM E agora? Assim como este erro ocorreu podem ocorrer outros erros que eu nem mesmo tenho conhecimento. Como farei para tratar esta exceções? Ai que entra em ação a (quase) fantástica funcionalidade do Elastic Stack, (vou tomar a liberade de chamá-lo de DLQ). Na seção ‘Não é bala de prata’ vocês entenderão por que uso o termo (quase) fantástica funcionalidade. Dead Letter Queue Como funciona? O DLQ é um componente configurável no Logstash que fará o papel de monitor de falhas sobre algum pipeline dentro do Logstash, uma vez que este pipeline falhar terá outro pipeline que fará uma nova tratativa de envio destes dados. Como configurei meu ambiente para o DLQ? Hey, eu utilizo o CentOS Server 7, OK?! Ativação da funcionalidade DLQ Editei o arquivo de configuração do Logstash, no meu ambiente ele está em /etc/logstash/logstash.yml. A a alteração ficará (simplesmente) como abaixo # ------------ Dead-Letter Queue Settings --------------
# Flag to turn on dead-letter queue.
#
dead_letter_queue.enable: true Criação de novo arquivo que conterá o pipeline do DLQ Criei o arquivo o arquivo logstash_dlq.conf em /etc/logstash/conf.d/ input{
        dead_letter_queue{
                id => deadletter
                path => commit_offsets => pipeline_id => }
}
filter {
        mutate {
                add_field => { => => => => }
        }
}
output {
        elasticsearch{
                id => cluster1
                hosts => [ , , ]
                user => password => index => }
} "/var/lib/logstash/dead_letter_queue" true "main" "reason" "%{[@metadata][dead_letter_queue][reason]}" "plugin_id" "%{[@metadata][dead_letter_queue][plugin_id]}" "plugin_type" "%{[@metadata][dead_letter_queue][plugin_type]}" "entry_time" "%{[@metadata][dead_letter_queue][entry_time]}" "serveElasticsearch01" "serveElasticsearch02" "serveElasticsearch03" "${ES_USR}" "${ES_PWD}" "dead-letter-%{+YYYY.MM.dd}" Apontamento do Logstash para o pipeline O apontamento dos pipelines ficaram conforme o arquivo de configuração abaixo. Arquivo localizado em /etc/logstash/pipelines.yml # This file is where you define your pipelines. You can define multiple.
# For more information on multiple pipelines, see the documentation:
#   https: - pipeline.id: main
  path.config: - pipeline.id: deadletter
  path.config: //www.elastic.co/guide/en/logstash/current/multiple-pipelines.html "/etc/logstash/conf.d/logstash.conf" "/etc/logstash/conf.d/logstash_dlq.conf" Por fim basta reiniciar o Logstash. . [Farei um post futuramente explicando os motivos que me levou esta abordagem e como fazemos para realizar a gestão de falhas no dia a dia] Após isso o Logstash criará índices no ElasticSearch no padrão ‘dead-letter-%{+YYYY.MM.dd}’ Não é bala de prata Mágico não é?! Vamos devagar pessoal, realmente a funcionalidade é muito válida e interessante, mas vale resaltar alguns pontos que devemos ter conhecimento para não nos surpreendermos depois que estiver com tudo em produção. DLQ trata erros que são retornos com códigos . HTTP 400 e 404 DLQ faz apenas uma nova tentativa por mensagem, se ocorrer o erro novamente a mensagem não será tratada. DLQ gera arquivos de controle da fila que não são apagados automaticamente, caso observar grande consumo de disco remova os arquivos de logs antigos, arquivos em /var/lib/logstash/dead_letter_queue. E por fim… Esta post foi feito com base em um caso real sobre a versão 7.7.1 da Stack Elastic.Estes links podem apoiar nos estudos sobre o tema: https://www.elastic.co/guide/en/logstash/current/dead-letter-queues.html https://discuss.elastic.co/t/full-pipeline-logstash-with-dead-letter-queue/239855/3 https://www.hostinger.com.br/tutoriais/o-que-e-http-error-e-principais-codigos-http/ Caso ainda tenham dúvidas podem contar comigo.

Dead Letter Queue no Elastic Stack

During my own preparation for Winter 2018 class interviews, I’ve reviewed every public resource on the topic and did over 20 practice interviews with Y Combinator alums. Everything I’ve learned is summarized below. This guide is my personal take and doesn’t represent an official position of YC. Along with this guide, you can also read and reuse our YC interview answers . To get more help, join a chat community of startups applying to YC . Answers development The core of your preparation process is writing a document with all anticipated questions and your answers to them. Start with the items below, then expand by adding answers to new questions asked at your practice interviews. Answers document. Your first sentence in the interview is either a solution description or value proposition. It should be 4–8 words long and pass the “mom’s test”, i.e. your parents should be able to repeat it back to you. Opening description. Define 3 core strength points in advance. Steer conversation to hit them all, sometimes even regardless of questions.Types of strength: revenue/growth/traction, domain expertise/done this before, insight aka “a-ha moment”, market size.Consider repeating or rephrasing your top three points when you aren’t sure they landed well the first time.Test your strength points: Will someone be excited about your company if she/he only hears the one-line description and three strength points? Strength points. Those are anecdotes, quotes, or factoids that receive consistent “a-ha” and “hmm.. interesting” reactions during your practice runs. Insights. Know your 2–3 key weakness areas and prepare short, crisp answers to most common concerns.For every question that you don’t answer with a strength point or an insight, limit yourself to one sentence. You want to maximize the time for strength discussion, not secondary issues. If you use the second sentence, it should go back to strengths or insights. Defense. How to write strong answers Use a lot of factoids and numbers. Your answers document should have at least 20–30 answers with numbers. Whenever possible, eliminate verbs from answers. E.g. “What’s your go-to-market?” — “A, then B, then C”.Use simple words and examples, avoid buzzwords or abstract concepts. For questions on weakness areas, acknowledge or defend it in one sentence, then go back to strengths in the second. Use examples and facts over forward-looking plans. “In the past, we’ve solved it by X with results Y”.Explain implications: “if we achieve X (hard, but possible technical achievement), then we will get Y (major business win)”. Whenever possible, use primary data from customers instead of analogies. Generally, YCombinator doesn’t see analogy-based arguments as reliable or strong.Avoid top-down market sizing. Either do bottom-up or close comparables. “Sell your co-founder”, be ready to tell why your partner is great. Practice runs Schedule at least 10–20 practice runs. For mock interviews, ask investors and founders you already know, YC alums from your city / country / university, YC alums in your industry or with a similar business model, and YC alums who volunteer to do practice interviews on Twitter. You don’t need an intro. Ask early, at least 7–10 days before your interview day. Take notes and rewrite your answers after each practice run. Do a debrief with each mock interviewer. Ask which answers were clear and strong, and which ones were not. Discuss how to improve your individual answers. Iterate on your top strength points, unique insights/anecdotes, and defense answers. Additionally, watch YC’s public office hours (links below) to get a feel of YC interview format. Interview day Arrive early, identify your room and learn who is on your panel, research panel partners in the remaining time. Make new friends with fellow applicants. Have the demo ready on the laptop with all important screens in multiple tabs. Don’t rely on YC WiFi.Assume that YC partners have no prior knowledge. Review partner’s bios in advance, identify partners who can become supporters due to their personal interest in your space. From YC’s standpoint, the purpose of the interview is to extract as much info as possible in 10min. At least one of YC partners will look closely for body language and nonverbal signals. Expect 40–80 questions in 10 minutes, 8–12 seconds per question-and-answer round. Be ready for constant interruptions (even after the first 2–3 words of response). Be ready for unique questions outside of your list. Be ready for parallel interview with multiple co-founders (not very common). Be ready for a narrow and deep drill on a single question, most likely related to your biggest weakness. Logistics and expectations. Talk fast, but not super fast. Feel happy, high-energy, and excited to pursue the opportunity. Be casual and friendly, maintain eye contact. Be confident, yet humble. Confident and concise = formidable. A few weak answers are ok. A long weak answer is much worse than a short acknowledgment like “I don’t know” or “we plan to work on this”. Don’t be too defensive, show coachability. Consider repeating or rephrasing your top three points, if they weren’t well received the first time. Most answers should be one sentence, some can be two sentences. Limit yourself to only 2–3 longer replies throughout the interview. Don’t interrupt each other, don’t argue on unexpected questions. Instead, say “yes and …” or “and I’ll add to this…” to continue after your co-founder. When disagreeing with YC partner’s statement, either give counter-facts or accept it as a hypothesis to test. Don’t make straight deflections. Answer the question asked, before changing direction. When challenged on critical hypotheses for your business, be ready to push back with crisp defense and facts. When the conversation goes sideways, try to steer it back to strengths, e.g. “and I want to make sure you hear this…”. Interview time. Interesting problem. Ideally, unique or novel. Otherwise, a new insight or approach. Compelling value proposition. Clear and concise solution description. Clarity on how the hard parts of the solution work. Inspiring mission. Market size and dynamics. A small but rapidly growing market is always compelling. Insightful ideas for overcoming market-specific concerns. Activation of “spidey sense” i.e. “hmm… something interesting should happen in this space” feeling. Team with deep relevant expertise and domain knowledge. Strong communication skills: crisp, short, clear answers. Competitive landscape fluency. Proven rapid pace of making progress. Energy and resourcefulness, “get things done” attitude. Coachability, being good at taking feedback constructively. Determined, yet flexible. Original thinking and learning ability. Unconventional points of view and insights directly from customers. Positive team dynamics, no interruptions or arguing, alignment on vision. Low chance of founder conflict. Good English and easy-to-understand accent, no language barriers in communication. Ability to inspire and recruit star team. Make YC partners want to work for you. Can grow into “forces of nature”. Direct path to building momentum by the end of YC program aka “become a hot seed deal”. Direct path to hitting high revenue in 2–3 years aka “getting big”. Expected YC evaluation criteria. Y Combinator Interview Resources , , , , . Official resources: list of partners preparation advice preparation advice video old advice Michael Seibel’s 7 points , , , , , , , , , , , , . Advice from alums: Quora thread Kwindla Hultman Kramer Henrik Zillmer Tristan Zier Barak Ben Ezer Scott Wheeler David Rusenko Sumon Sadhu Robby Walker Natalie Bartlett Fabrizio Buzeto GetAccept Gareth MacLeod , , , , . Question collections: PG Simulator Aptible Brad Flora TechCrunch QZ , , , , , , , , , . Public office hours: SS 2011 SS 2013 SS 2014 SS 2014 NYC TNW 2014 SS 2016 SS 2016 SC17–1 SC17–2 SC17–3 Acknowledgments I am forever grateful to everyone who helped us through the process: Hrachik Adjamian, Daniel Ahmadizadeh, Andrew Arruda, Delian Asparouhov, Chas Ballew, Kirill Belov, Eva Breitenbach, Matt Brezina, Tom Broderick, Levon Brutyan, Jeremy Cai, Dan Carroll, Deepak Chhugani, Nick DeMonner, Dmitry Dumik, Evan Farrell, Herbie Fu, Jim Gibbs, Anton Gladkoborodov, Allan Grant, Vlad Gurgov, Chetan Jhaveri, Ryan Johnson, Dave Kim, Alexander Kim, Kwindla Hultman Kramer, Sam Lang, Clarence Leung, Bowen Lu, Max Musing, Ivan Novikov, Thomas Pun, Roberto Riccio, Wen Sang, Boris Silver, Preston Silverman, Zac Townsend, Brett Van Zuiden, James Vaughan, Praveen Venkatesan, Tracy Young, Diana Zink. Good luck! To get more help, join a . I am frequently there to help with any preparation questions you might have. chat community of startups applying to YCombinator

The Ultimate Guide to YCombinator Interview Preparation

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Levo

levo.ai

11-50 employees

Since 2021

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LEVO

EVERGREEN INDEX #7194

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