MentionFox lists 83 Developer tools companies for 2021. Of them, 83 are Y Combinator companies (the newest batch here is Summer 2021, with 42).
Companies83
Y Combinator83
Other years
All years (678) 2026 (89) 2025 (82) 2024 (91) 2023 (79) 2022 (64) 2020 (54)
Developer tools startups in 2021
| Company | What it does | Date | Amount | Round / stage | Record |
|---|---|---|---|---|---|
| Abatable | Carbon markets platform and solutions | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Anakin | One API to get clean data from any website for your AI agents at scale | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Archbee | TURN STATIC DOCS INTO INSTANT ANSWERS | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Arengu | Build frictionless signup flows in minutes | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Artillery | The complete production quality platform | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| aSim | Build and share apps with friends | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Aviator | Google-level engineering productivity suite | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Awesomic | Get matched with top 1% of talents in 24h | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Breadcrumbs.io | No-code scoring engine identifying your most engaged upsell opps | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Buró de Ingresos | The Work Number for LatAm | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Cloudanix | Cloud and Container Security Platform | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Cloudthread | Eliminate Cloud Waste | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Coast | Demo Platform for API-First Companies | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Cumbuca | Bare-metal access to Brazil's Open Finance and Pix systems | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Dailybot | Make all team work visible — people and AI agents | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Dots 💸 | Developer friendly drop in payouts infrastructure | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Echoes HQ | Measure and communicate engineering activity | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Evidence | Business intelligence as code | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Evidently AI | Open-source monitoring for machine learning models | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Exa | Web search rebuilt for LLMs | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| hotglue | Native user-facing SaaS integrations for your customers | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Hyperbrowser | Web infra for AI agents | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Jovian | Online University for Tech Professionals | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Keyri | Secure fraud prevention and authentication platform for developers | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Medium Biosciences | AI-designed Affinity Reagents | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Mergent | Incredibly reliable background task queues and cron jobs | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Meticulous | Automated e2e screenshot testing without writing or maintaining tests | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| MobileBoost | AI native mobile testing. | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Noloco | Flexible Business Apps for Modern Teams | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Pipekit | Pipekit scales data & CI pipelines for enterprises | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Pluggy | Plaid for Brazil: we allow developers to access users' financial data | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Replo | Sell anything | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Rootly | AI-native on-call and incident response carefully crafted to help… | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Satsuma | Reliable blockchain indexing & querying for web3 engineering teams. | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Strive Math | Online Coding School for Kids 8-16 | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Superwall | Subscription infrastructure & paywall experimentation for mobile apps | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| testRigor | Executable specifications in English for test automation | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Union54 | Developers of ChitChat, an integrated messaging and payments wallet… | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| WarpBuild | Accelerate software development with WarpBuild's 10x faster CI infra. | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Warrant | Authorization and access control as a service. | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Whalesync | Manage your website from your favorite tools like Airtable and Notion | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| zaz⚡️os | The custom all-in-one OS for each company. | Summer 2021 | Y Combinator batch | Y Combinator listing | |
| Alokai | Frontend Platform for eCommerce | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| authzed | Winter 2021 | Y Combinator batch | Y Combinator listing | ||
| Avenue | Observability platform for operations teams | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Axolo | Improving Developer Experience with Streamlined Code Reviews | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Curvenote | Communication and publishing tools for scientists | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Dyte | Real-time audio & video SDKs, ready to launch 🚀 | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Emerge Tools | Supercharge your mobile apps | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Enode | Energy Orchestration Platform | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| FifthTry | Continuous Documentation To End Documentation Rot | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Fintoc | Account-to-Account payments in Mexico and Chile. | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| FlutterFlow | Application Development Platform (Native Mobile + Web Apps) | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Friz | AI Social Media Manager | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Gigs | The OS for Embedded Telecom | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Haystack | Delivery Analytics for Software Teams | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| hoop.dev | Code review for DevOps tasks | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Howdy.com | We help US tech companies hire and manage software engineers in LATAM | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Hubuc | Global Card Issuing and Payment Processing Engine | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Infracost | Shift FinOps Left: Proactively Find & Fix Cloud Cost Issues | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Kitemaker | A faster and more collaborative alternative to Jira for remote teams | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| LogisticsOS | World's fastest and most optimal route optimization engine | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| MagicBell | The notification inbox for web/mobile applications. | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Manara | Connecting top Middle East talent to global tech jobs | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Mindee | AI Document Understanding API | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Ollama | Get up and running with large language models. | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| OpenCode | The open source AI coding agent | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Pyroscope | Open source continuous profiling software to debug performance issues | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Quicknode | Tools & infra to build and scale high-quality blockchain applications. | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Rulebricks | Add powerful decision-making capabilities to any automated workflow. | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Runway | Easier and more reliable mobile app releases for teams. | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| SigNoz | Open source alternative to DataDog | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Smartcuts | Chrome extension to turn clicks & keystrokes into no-code automations | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Svix | Enterprise ready webhooks service, open-source and in the cloud | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Taloflow | Better, faster tech vendor research | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Terra Api | API for developers and AIs to access health data | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Tint | Makes it easy for tech platforms to embed insurance into products | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Uiflow | No-code platform for enterprise software companies | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Vapi | Voice AI for developers. | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Wasp | Configuration language for building enterprise web apps 10x faster | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Waydev | Engineering intelligence for AI transformation | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| Webiny | Open-source framework for building serverless applications | Winter 2021 | Y Combinator batch | Y Combinator listing | |
| weweb.io | WeWeb is the AI app builder your IT team will approve. | Winter 2021 | Y Combinator batch | Y Combinator listing |
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Figures come only from the record linked in each row; a blank means the record gives none. How these lists are built.