TENDERLY

Three Serbian engineers — Andrej Bencic, Bogdan Habic, and Srdjan Kobiljak — were building on Ethereum in 2018 and kept hitting the same wall: when their smart contracts broke, they had almost no way to figure out why. Ethereum gave you a revert with an error code.

That was it. No stack trace.

No line-by-line debugger. No way to replay the transaction and see what went wrong at each step.

So they built the tool they needed. They launched Tenderly as a smart contract debugging and monitoring platform, initially targeting Ethereum developers who were building DeFi protocols.

The timing was perfect — the DeFi boom of 2020-2021 meant thousands of developers were writing serious financial code on blockchains with essentially no professional tooling. Tenderly filled the gap that Ethereum's core infrastructure had ignored.

Tenderly runs a freemium SaaS model. Individual developers get free access to basic debugging and transaction simulation — this drives adoption and word of mouth.

Teams and protocols pay for higher-tier plans covering private simulations, monitoring at scale, API access, and custom alerting. Enterprise customers — major DeFi protocols, exchanges, and Web3 infrastructure companies — pay for dedicated infrastructure, SLAs, and advanced analytics.

The core hook is a debugging workflow that developers try once and immediately cannot imagine building without.

The Transaction Debugger is the flagship — it lets developers replay any on-chain transaction with a full execution trace, showing exactly which line of which contract executed at each step. Transaction Simulation lets developers test what a transaction will do before sending it, which is critical for DeFi protocol builders who cannot afford mistakes in production.

DevNets gives teams a private fork of any blockchain for testing in a realistic environment without touching mainnet. The Monitoring & Alerting system watches live contracts and triggers notifications when specific conditions occur — an invaluable tool for protocol security teams.

Tenderly grew by becoming essential. Every time a DeFi exploit happened — and 2020-2022 was full of them — security researchers used Tenderly to trace exactly what occurred, step by step.

Those post-mortems got published on Twitter and in protocol forums, and every developer reading them saw Tenderly in the screenshots. The platform sold itself through the forensic clarity it provided after disasters.

That's a distribution strategy nobody planned for but couldn't have engineered better if they'd tried.

They also expanded horizontally. What started as a debugger became a full developer platform: transaction simulation before execution, monitoring and alerting for live contracts, fork-based testing environments (DevNets), and eventually node infrastructure (Web3 Gateway).

Each expansion gave existing users more reasons to stay and new users reasons to start.

The crypto market collapse of 2022 hit Web3 developer tooling companies hard. Many of Tenderly's customers were protocols whose token treasuries had declined 80-90%, slashing their operational budgets.

Retention became a challenge. Tenderly also faces competition from every direction — Alchemy offers overlapping node infrastructure, Hardhat and Foundry are free open-source alternatives for testing, and Etherscan offers basic transaction tracing for free.

Moving upmarket to enterprise customers while remaining beloved by indie developers is a tension every developer tools company eventually has to navigate.

Accel Partners led both the Series A and Series B, which is a strong signal — they don't usually come back for more unless they like what they see. Point Nine Capital backed the initial seed round.

Coinbase Ventures participated, which matters because Coinbase is both an investor and a potential enterprise customer. Nexus Venture Partners also participated.

The investor base reflects both pure VC conviction and strategic interest from ecosystem players who benefit from Tenderly improving Ethereum developer experience.