Senior Software Engineer (Full-Stack)

Signifly; København; On-site; DKK 900,000 - 1,200,000; Full time

Benefits offered by this job

Team trip

Catered lunches

Drinks on Fridays

Modern office

Equipment provided

In-office massage

Conference trips

Pension and health insurance

Career progression

Exchange program

Job summary

Signifly is seeking a Senior Software Engineer to join our Tech team in Copenhagen and help shape how we build with AI. You will work as a senior full-stack engineer on diverse client projects, using TypeScript, Next.js and React at the core, with backend services and integrations as needed.

You will contribute to AI-powered features, agentic development, and maintain strong fundamentals in architecture, code quality and judgment while collaborating across offices in Copenhagen, Montreal, London

Qualifications

• Solid experience as a senior full-stack developer with modern TypeScript and Next.js/React.
• Hands-on experience with AI-assisted and agentic development and APIs.
• Ability to own architecture decisions and drive technical direction.

Responsibilities

• Shape, build and improve digital products end to end from frontend to backend.
• Inspire adoption of agentic engineering and share learnings with the team.
• Build AI-powered features and agentic systems for client products.
• Take technical ownership on projects including architecture and quality.
• Lead by example in development practices and cross-team collaboration.
• Stay ahead of trends and bring them into the team to improve services.
• Support Signifly teams with technical knowledge and mentorship.

Skills

Full-stack development

TypeScript

Next.js/React

Node.js

APIs

Databases

AI-assisted development

Agentic development

Claude Code

Tools

Claude Code

Job description

We are looking for a Senior Software Engineer, who will like to joinour Tech team in Copenhagen!

We're looking for a senior full-stack engineer to join our Tech team in Copenhagen. Someone who's excited about where software development is heading and wants to help shape how we build with AI.

As a member of our Tech team, you'll be an essential part of developing digital products together with our clients and the team around you. Since we're an agency, we work with a wide range of clients, typically in focused sprints where we build new products or improve products we've built with them before. Our stack is TypeScript with Next.js and React at its core, extending into backend services, APIs and integrations as projects demand.

We're operating in a time of agentic engineering. AI agents are changing how software gets built, and we embrace that: we use agentic tools to ship faster and build AI-powered features into client products. At the same time, we know that reaching the quality we aim for means sticking to the fundamentals of good software development. Agents amplify good engineering, they don't replace it. We're looking for someone with strong fundamentals in architecture, code quality and judgment, who can put these new tools to work without compromising on craft.

We have an excellent team across our Copenhagen, Montreal, London and Toronto offices. We'll throw challenges at you, teach you new things, learn from you, and make sure we grow together toward our ambition of setting new and higher standards for the web.

Check out some of our work HERE.

Key tasks:

• Shape, build and improve digital products end to end, from frontend (Next.js/React) to backend services, APIs and integrations
• Inspire adoption of agentic engineering: use AI coding agents in daily work and share learnings and insights with a team that explores and grows together
• Build AI-powered features and agentic systems into client products, such as MCP/LLM integrations, automations and intelligent product experiences
• Take technical ownership on client projects: architecture decisions, technical direction, and quality
• Lead by example on good development practices and ways of working, across both technical and non-technical team members
• Stay ahead of new trends and bring them into the team so we keep delivering top services to our clients
• Support with tech knowledge and skills across Signifly's different teams

What we expect of you:

• Solid experience as a full-stack developer in a similar senior position, and strong with modern TypeScript, Next.js/React and backend development (Node.js, APIs, databases)
• Hands‑on experience with AI-assisted and agentic development (tools like Claude Code or similar) and real curiosity about pushing this frontier
• Experience building AI-native APIs and product features is a big plus
• You're good at understanding real‑world client problems and proposing smart technical solutions to address them
• You thrive in helping others, whether it's a client, a project manager, a developer colleague or the sales team
• You take ownership: of your code, your projects, and the growth of the people around you

Please expect no less from us:

The most important thing that we offer is an inspiring and ambitious work environment, with an emphasis on learning and developing, both personally and as a team. We have an informal organization with minimal hierarchy, where there is plenty of room for being ambitious within your own area of expertise, as well as taking part in shaping our team, culture, and product offering.

But, of course, we can also tempt you with:

• Yearly one-week team trip with both social and professional focuses (paid)
• Fresh catered lunch of mostly organic produce and with vegetarian options
• Coffee, tea, soft drinks, snacks, etc. - and wine, beer and drinks on Fridays
• Beautiful office space with emphasis on noise reduction, centrally located in Vesterbro
• Paid equipment of high quality - you choose what you prefer
• In-office massage service
• Inspiration-trips to events, meet‑ups, and conferences
• Company paid pension and health insurance
• Competitive salary based on qualifications and performance
• Career progress based on merits rather than seniority
• Opportunity to work-exchange with our office in Montreal, London and Toronto

And if you think something is missing, just let us know. We can probably work together to add it. After all, we are trying to create the best possible place to work!

About Signifly

Signifly is one of the fastest growing agencies in Denmark, and our young and energetic team has won several awards for our innovative approach to digital products and user experiences. We are a young and ambitious team that are constantly pushing the limits for our work and our own capabilities.

At Signifly, we collaborate with a broad range of clients from all industries, to create new and innovative digital products and business models. We are a team of developers, designers, film makers and digital strategists, and we believe that creativity, entrepreneurship and a diverse mix of top‑notch skills can drive the innovation and change that will help shape a better tomorrow.