Senior Full-Stack Engineer – Automation & Integrations

Company: Leadinfo

About the Role

We are looking for a Senior Full-Stack Engineer to take ownership of our email and LinkedIn automation platform and workflow builder. This role combines backend development, frontend engineering, infrastructure, and deep technical ownership of a key product area.

You will work hands-on on production systems, maintaining and extending our automation platform, supporting integrations, and improving deliverability and reliability. You will also contribute to architectural, security, and infrastructure decisions, and take responsibility for the technical health of this part of the product.

We’re looking for a product-minded engineer who cares deeply about reliability and user experience. You are a strong problem solver who can operate autonomously and take ownership of your work. You’re comfortable wearing multiple hats — from developer to infrastructure owner to technical support lead — and you communicate clearly while collaborating effectively with engineering, product, and customer success teams.

What You’ll Do

In this role, you will design, develop, and maintain RESTful APIs using PHP with the Slim Framework. You will implement the core business logic behind automation workflows, data processing, and system orchestration. You will be responsible for maintaining PostgreSQL databases, including per-customer schemas, migrations, and performance optimization.

On the frontend, you will build and maintain React components for the workflow builder and automation interfaces. You will manage application state and real-time updates using WebSockets, and work closely with product and UX to improve usability and reliability.

You will also take ownership of infrastructure and operations. This includes configuring and maintaining AWS services such as ECS (Fargate), Elastic Load Balancers, CloudWatch, Secrets Manager, and related networking and security services. Monitoring system health, performance, and error handling is a core part of the role.

Beyond the core platform, you will develop and maintain Node.js services used for background jobs and integrations. You will handle third-line technical support escalations together with Customer Success, perform root-cause analysis, and implement long-term fixes. You will contribute to security best practices, compliance and data protection requirements, and the technical preparation for CASA certification and similar standards.

Domain-Specific Responsibilities

A significant part of the role focuses on systems related to email and LinkedIn automation. This includes working with email automation using SMTP and IMAP, improving deliverability and sending reputation, maintaining LinkedIn automation and integrations, and building and supporting multi-step outbound workflows.

You will work with browser automation tools, including existing Puppeteer workflows that are being phased out, and integrations with third-party automation providers. You will also maintain and extend a Chrome extension written in JavaScript and TypeScript that supports browser-based automation workflows.

Who are you

• You have strong experience with PHP (Slim Framework), Node.js, React, PostgreSQL, and AWS production infrastructure.
• You have a solid understanding of REST APIs, asynchronous systems, and distributed services.
• You have experience debugging production systems and handling live incidents.
• You are comfortable working across backend, frontend, infrastructure, and support contexts.
• You are able to work independently and take full ownership of a product area.

What do we offer?

• An international team with enthusiastic colleagues.
• A clear career path with international growth opportunities.
• 26 vacation days plus an extra day off on your birthday.
• 8% holiday allowance per year.
• A solid pension plan.
• A hybrid working model: partly in the office, partly from home.
• A flexible monthly budget of €50, for example for sports, hotel stays, meal boxes, and more.
• Access to the OpenUp platform, giving you and your loved ones easy access to professional mental health support whenever it’s needed.
• The option to work fully remote for 2 weeks per year.
• Everything you need to perform: tools, training, and support.
• Daily lunch and snacks.
• Table football, Xbox, and Mario Kart to relax during the day.
• Friday afternoon drinks and regular social events and parties.