Job Description

ABOUT THE COMPANY:

Join ADDENDUM, a global software development and IT team augmentation firm focusing on fintech, banking, and telco industries. Experience tailored benefits, diverse projects with various tech stacks, and opportunities for growth, freedom, and responsibility you desire.

ABOUT THE ROLE:

Join a team of experienced IT professionals working on an exciting securities trading project in the banking sector, with a focus on trading automation, system integrations, and backend development.

As a Senior Software Developer, you will play a key role in designing and delivering secure, scalable backend solutions and automation enhancements that reduce manual processing, improve operational efficiency, and support faster securities settlement.

Location: Tallinn, Estonia. Candidates must be based in Tallinn, as a hybrid working model applies to this position.

Start date: From 16 November 2026 (earliest possible start).

WHAT YOU WILL BE DOING:

• Design, develop, test, and document backend functionality for the Trading Automation project.
• Develop secure, scalable, and maintainable solutions using Java or Kotlin, Spring Boot, and REST APIs.
• Build and enhance system integrations within an existing application landscape.
• Work with relational databases, including data modelling, SQL development, and query optimisation.
• Translate business requirements into technical solutions, making well-founded architectural and design decisions.
• Take ownership of agreed project deliverables, ensuring high-quality implementation within defined timelines.
• Collaborate closely with business stakeholders, developers, architects, and other technology teams.
• Participate in code reviews, testing, and technical documentation to maintain high software engineering standards.

WHAT WE EXPECT:

• Extensive professional experience in backend software development, with a proven track record of delivering complex, integrated, or business-critical systems at a senior level.
• Strong expertise in Java or Kotlin, Spring Boot, and API design and development.
• Solid experience with relational databases, including data modelling, SQL, and query optimisation.
• Proven ability to independently translate business requirements into secure, scalable, and maintainable technical solutions.
• Hands-on experience developing system integrations and implementing changes within existing enterprise applications.
• Strong understanding of software engineering best practices, clean code principles, code reviews, and technical documentation.
• Ability to independently manage assigned deliverables, make technical decisions, and take responsibility for the quality of solutions.
• Excellent communication skills in English.

Nice to have:

• Experience with Angular or other frontend technologies.
• Previous experience in securities trading, investment services, banking, or financial markets.
• Familiarity with securities settlement processes and trading automation.

WHAT WE OFFER:

Compensation: We offer competitive market-based remuneration under either a B2B contract or a regular employment agreement. The compensation package is determined individually and is highly dependent on your professional experience, qualifications, and expertise.

At Addendum we believe in personalized benefits packages that cater to your unique passions. Tell us what drives you, and we'll craft a package accordingly. On top of that, here's what's in store automatically:

• Top Talent Collaboration: Join award-winning teams from different countries.
• Diverse, Challenging Projects: Break free from the ordinary with dynamic, stimulating work.
• Epic Team Events: Join us for summer and winter parties and online events.
• Learning & Development Opportunities: That new tech certificate is just around the corner.
• Special Celebrations: We love a good shindig for birthdays and project milestones.

So, get your dancing shoes on and come join the fun!

At ADDENDUM, we wholeheartedly reject all forms of discrimination, including but not limited to age, disability, sex, sexual orientation, pregnancy and maternity, race or ethnicity, religion or belief, gender identity, marriage, civil partnership, or any other protected category. We are committed to fostering a culture of equality and inclusion, where every individual has the opportunity to thrive.