AI Software Engineer

Renessai Oy; Helsinki; Hybrid; EUR 70,000 - 100,000; Full time

Job summary

Renessai Oy is seeking an AI Software Engineer focused on agentic software where agents form the core of client systems. You will design tool design, memory, orchestration, and context to enable scalable agent-based workflows.

Role emphasizes building with coding agents and orchestrators, delivering rapid early versions, and close client collaboration to refine and improve systems based on real usage.

Qualifications

• Hands-on experience building agentic systems including tool design, context, memory, planning, and orchestration.
• Experience running AI evaluations and weighing quality vs. cost.
• Daily fluency with coding agents and tooling beyond prompting.

Responsibilities

• Design and build agentic workflows and multi-agent setups where appropriate.
• Define where agent use is appropriate vs. deterministic software.
• Establish guardrails and governance for production systems focusing on cost, scalability, and trustworthiness.

Skills

Agentic engineering

AI evaluations

Coding agents

Cloud platforms

Tools

Azure

GCP

AWS

Job description

About the role

We build AI-native software for clients: systems where agents do real work, not systems with a chat window bolted onto the side. We are looking for an AI Software Engineer whose home ground is the agentic layer, meaning tools, context, memory, orchestration, and the evaluations that tell you whether any of it actually works.

Two things define this role. First, agents are what we build: the core of most client systems we deliver is an agentic workflow. Second, agents are how we build: we develop with coding agents, skills, and orchestrators as the default way of working, and part of your job is making that way of working faster and more reliable for everyone around you.

You will ship early and learn from real use. That means rapid discovery, small real versions built to test a hypothesis, and a willingness to drop last week's idea when the feedback says so. It also means working close to the client and the people who use what you build, rather than at a comfortable distance from them.

What you will do

Build agentic systems as the core of client software

• Design and build agentic workflows: tool design, context engineering, memory, planning, and orchestration, including multi-agent setups when the problem genuinely calls for them.
• Decide where the agent ends and deterministic software begins. Not everything should be an agent, and knowing the difference is a large part of the job.
• Design the guardrails and human oversight a system needs to be trusted in production, and treat cost, scalability, and trustworthiness as design questions rather than things to fix later.

Build and run the evaluations

• Set up evals that test quality, catch regressions, and track performance against cost: accuracy, drift, correction rate, quality gating.
• Treat evals as part of the system, not a report produced at the end. If we cannot measure whether the agent got better, we do not know whether it did.

Build the way we build

• Set up the skills, harnesses, subagents, and context a project needs, and shape a development workflow where agents do a large share of the implementation and humans stay firmly responsible for the result.
• Keep improving that workflow as models and tooling change, which at the moment happens roughly monthly.

What you bring

You do not need every item below. You should be confident in several and willing to grow into the rest.

Agentic engineering

• Hands-on experience building agentic systems: tool design, context, memory, planning, orchestration. Your opinions on these come from things breaking in real projects, not only from reading about them.
• Practical experience building and running AI evaluations, and the judgement to weigh quality against cost.
• Daily fluency with coding agents (Claude Code, Codex, Cursor, or similar) that goes well past prompting: skills, subagents, parallel runs, and a working sense of what to delegate and what to verify yourself.

Software engineering

• Solid experience with at least one major cloud (Azure, GCP, or AWS), including setting up infrastructure, access, and governance.
• Enough backend and frontend experience to take a real system from architecture to interface without needing each piece handed to you as a finished spec.
• Practical experience with data pipelines: moving and synchronising data, including at larger scale.

Consulting skills and mindset

• Comfortable being close to the client and the people who will actually use what you build.
• Able to read a client's business context and users' needs well enough to make good calls without a full specification in hand.
• Willing to ship early, test with real users, and change direction when new information tells you to, rather than defending a plan.
• Tolerant of ambiguity and of things being unfinished.
• Straightforward and easy to work with, in a small, evolving company.

Why this role might be interesting for you

You'll own real pieces of the stack, work directly with clients, and get to define how AI-native development actually works here, we're still figuring a lot of this out, even ourselves.

Practicalities

• Location: You must be based in Finland and have a valid work permit in Finland.
• Office presence: This is a hybrid role so we’ll expect you to come into our Helsinki office roughly once a week. Client site presence is subject to project and client needs.
• Salary: we have a salary range per role based on experience. We're happy to talk about this early rather than late.