Staff Software Engineer

Tact; Greater London; Hybrid; GBP 135,000 - 165,000; Full time

Job summary

Tact in London is hiring a Staff Software Engineer to own hands-on coding and architectural direction for a product-focused SaaS platform. The role combines production-grade engineering with real influence over what gets shipped, in a hybrid/remote setup.

You will work on agentic AI products in production, collaborating with Product and Design, and you’ll join engineers from top tech firms who value autonomy, trust, and technical challenge.

Qualifications

• Hands-on software engineer who writes production code.
• Has owned complex software systems and made architectural decisions.
• Familiar with AI tooling and modern ML/AI development workflows.

Responsibilities

• Design, code and ship full-stack software across the product.
• Influence architecture and engineering standards.
• Develop agentic AI products with enterprise customers.

Skills

Production code

Architectural decisions

Hands-on coding

AI tooling familiarity

Tools

Claude Code

Codex

Cursor

Job description

Staff Software Engineer | Up to £150K + Benefits | London, Hybrid/Remote.

No line management. No moving away from coding. Real architectural influence and ownership of what gets shipped.

You'd join a product focused SaaS company that's raised £25M, secured hundreds of established customers on long-term contracts and processed over £1bn through its platform already!!!

They're building agentic AI products already running in production, automating complex financial, compliance, and onboarding workflows. This is tough engineering challenges on the bleeding edge of the latest and greatest tech.

Real customers, real engineering challenges and an established product. Not another AI idea that's just been spun up yesterday and doesn't even have a codebase.

You could apply anywhere right now... this market is booming. So, why this one, right?

The engineering team and culture are what really stand out.

The team includes engineers from well-known tech startups and established FTSE companies. People who've worked in impressive engineering environments and chosen to join because of the technical challenges, calibre of people and culture.

It's built around trust, autonomy and freedom to build. Engineers are encouraged to challenge decisions, experiment with new technologies and take ownership without someone constantly looking over their shoulder.

They genuinely love geeking out over hard technical problems, debating architecture and sharing ideas.

You'll be surrounded by engineers who challenge you to get better, rather than being expected to be the smartest person in the room.

There is no way you don't become a better engineer here.

Your remit

• Remain 100% hands-on, designing, coding and shipping software across the full stack.
• Influence architecture, technical direction and engineering standards.
• Build agentic AI products already being used by paying enterprise customers.
• Work directly with Product and Design, shaping problems rather than just implementing tickets.
• Use Claude Code, Codex, Cursor and AI agents throughout the development lifecycle.
• Own complex engineering problems from initial idea through to production.

Who are they looking for?

• You love writing production code.
• You have owned complex software systems and made architectural decisions.
• You already use Claude, Cursor, etc for most of your development without compromising engineering fundamentals.
• You want to collaborate with talented engineers and challenging ideas. Not just be isolated and siloed.

You don't need to have held a Staff Engineer title. Principal Engineers, Tech Leads and even hands-on CTOs or Heads of Engineering could be relevant. As long as you love being hands on and building.

Why make the move?

You'll have the technical influence of a senior engineering leader without the people management, the freedom to make decisions without layers of approval and a team that genuinely enjoys building software together. Working on the bleeding edge of the newest tech at scale.

London:

Hybrid/Remote, the team goes in typically 1–2 days a week in the office, but it's not a non-negotiable you must be in. They understand you are an adult and you can be trusted to choose how you work best. It is your call.