- Building an AI-powered fintech SaaS product from scratch. - Establishing overall product architecture - Integration with third-party AI tools and models - Identity management and SSO - Data model and DB selection - DevOps processes

- As a member of the data science team established observable infrastructure for ETL pipelines enabling more flexible data search and providing better data for data-driven decision making. - Improved team efficiency by migrating a legacy Flask-based microservice to FastAPI making it more lightweight and providing better support for data validation. - Enabled automated SDK generation for a data science API improving velocity or peer teams consuming the API. - Integrated Open AI into product workflow. - Implemented a number of user-facing features of the freelance platform.

- As a solo-developer built a solution that eventually became the system that the Finnish Gymnastics Federation uses to host all of its competitions (over 200 per year, about 1000 to date). The system dramatically improved the efficiency of event organizers' work by consolidating all relevant data, making it available to external systems via API and providing a single modern responsive interface for all user groups. The system consistently gains high scores in surveys performed by the Federation. - As a response to Covid lockdowns, developed an extension facilitating virtual competitions by means of streaming pre-recorded performances. Over 100 competitions were hosted via the system and it helped to keep children active and motivated during lockdowns.

- Analyzed existing product architecture and identified its shortcomings. - Designed a way to introduce fault-tolerance into an existing business process automation application. - Designed a new cloud-native distributed application architecture to address its shortcomings by applying techniques like message-driven communication, event sourcing, consistent hashing, scalable NoSQL data store, and non-blocking execution. - Acted as a technical lead for a team of seven to ten people. - Created and implemented a reliable message processing framework with exactly-once processing semantics. - Designed a Cassandra-based application data model and implemented the functionality using this model. - Implemented a custom BPMN-based workflow engine to run automation workflows. - Participated in a few trial deployments of the new system.

- Re-implemented an existing PHP-based web app in Java, replacing a traditional server-rendered UI with SPA/REST architecture. - Established application back-end architecture, including data model, security, and an API. - Designed and implemented APIs to be consumed by SPA clients. - Implemented SPA client-side functionality using JavaScript. - Worked on improvements, including reliability, performance, and so on, in a distributed event processing platform. - Designed a way to deploy the existing telecom application as a virtual network function, i.e., made it cloud friendly, improved packaging and deployment, and more.

- Implemented a JMS-based inter-component communication framework. - Designed and implemented a layered protocol stack to deal with various aspects of provisioning, such as wire protocol, application type, target device, etc. - Implemented a workflow execution engine that resulted in performance improvements by order of magnitude. - Implemented data-model supporting multi-tenant SaaS. - Implemented integrations with partner systems using SOAP and REST.

- Developed an application platform for a family of network management applications. - Contributed to the high availability design of the application platform. - Built various features of a cellular network optimization tool. - Designed a single sign-on mechanism for Java Web Start applications.