# Tessl

AI Dev Tools · King's Cross · Series A

Tessl is building an AI-native software development platform based on spec-driven development, where engineers define specifications in natural language and AI agents build, test and maintain the underlying code. The goal is to shift software maintenance and evolution away from hand-written code toward durable specs. It was founded in 2024 by Guy Podjarny, previously founder of Snyk and CTO of Akamai. In November 2024 it raised $125M across a $25M seed (led by boldstart and GV) and a $100M Series A led by Index Ventures with Accel, at a reported valuation above $500M.

- Website: https://tessl.io
- Careers: https://tessl.io/careers/
- Sector: [AI Developer Tools](https://aistartupslist.co.uk/sector/developer-tools.md)

## Facts

- Funding stage: Series A
- Total raised: $125M
- Founded: 2024
- Headquarters: London, United Kingdom
- Team size: 11-50

## Notable investors

Index Ventures, Accel, GV, boldstart ventures

## Open UK & remote roles

- [Member of Technical Staff - Software Engineer](https://aistartupslist.co.uk/company/tessl/member-of-technical-staff-software-engineer-100kby.md) · London Office (posted 2026-08-11)
- [Member of Marketing Staff - Product Marketing Manager](https://aistartupslist.co.uk/company/tessl/member-of-marketing-staff-product-marketing-manager-1pnw78.md) · London Office (posted 2026-03-05)
- [Member of Technical Staff- Research Engineer (Harness Engineering and Agentic Orchestration)](https://aistartupslist.co.uk/company/tessl/member-of-technical-staff-research-engineer-harness-engineering-o254n.md) · London Office (posted 2026-05-28)
- [Member of Product Staff - Product Manager](https://aistartupslist.co.uk/company/tessl/member-of-product-staff-product-manager-1omkox.md) · London Office (posted 2026-06-25)
- [Member of Marketing Staff - Marketing Producer FTC](https://aistartupslist.co.uk/company/tessl/member-of-marketing-staff-marketing-producer-ftc-1gotk2.md) · London Office (posted 2026-08-17)