See Marcus’s profile in Swedish

Marcus Löf

Marcus is a software developer with experience in building robust, scalable solutions. He has primarily worked with backend development in Java and Kotlin for microservices and cloud services, but also has some experience across the full stack in multiple programming languages. He has worked with both maintenance and new development, and holds a Master’s degree in Engineering from KTH.

Marcus is a hardworking problem solver who is comfortable tackling complex challenges and is not afraid to roll up his sleeves to solve problems in uncharted territory. He has a strong focus on quality and thrives when building long-term, sustainable backend systems. Marcus is an excellent team player who puts the team’s success above his own. He is very unpretentious and actively works to ensure the best ideas are prioritized. Outside of work, Marcus enjoys training at the gym, competing in tennis, and playing chess.

Timeline

Assignment
In a team of seven developers, develop, design the architecture, and test software for a SaaS service in AWS that provides customers with smart data to make business decisions.

Impact
As a specialist developer, Marcus contributes to product development by designing technical solutions and architectures. He supports colleagues, acts as an ongoing mentor for junior developers, and brings both quality and energy to the team’s work to achieve product goals. Marcus also participates in requirements gathering, including leading and taking part in customer interviews, helping ensure the product is continuously improved based on user needs.

Technologies
Java, Kotlin, REST, Cucumber, Docker, Kubernetes, Elasticsearch, MongoDB, SQL, Redis, SOAP, RabbitMQ, Kafka, Python, Cassandra, Open Policy Agent (OPA), OAuth2, Bitbucket, GitHub, Bamboo, JSON, JWT, Yaml, AWS, Spring Boot, Ktor

2023 - (Current)

Developer Specialist

Large American company in data analytics

Assignment
Develop, modernize, and maintain systems for the company’s occupational pension business, which represents approximately 10% of Sweden’s non-collective occupational pension market. Marcus was part of a team of 4–6 developers. The systems included internal admin interfaces, pension insurance systems, external partner integrations, payment and fund distribution systems, billing systems, external web interfaces, as well as the company’s Corporate Web and Broker Web portals.

Impact
Marcus took significant responsibility for making the systems more robust and reliable. Legacy systems were migrated to a modern tech stack, and a new fault-tolerant billing system was built, including the ability to send invoices by email.

He actively contributed to the design and implementation of the new architecture during the migration and was a driving force in introducing automated testing into the build pipeline. This enabled efficient, high-quality delivery through continuous deployment and reduced the need for manual testing, both for web interfaces and APIs. When replacing legacy systems, comparative testing was used to ensure that the new system behaved correctly in relevant scenarios.

Technologies
Java, HTML, CSS, JSP, Angular, Typescript, Javascript, Kafka, gRPC, Cypress, Cucumber, Docker, GigaSpaces, MongoDB, SQL, REST, GitLab, Jenkins, JSON, Spring Boot

2022 - 2023

Developer

Modern Swedish digital bank

2021 - 2021

Tech Lead

Large American company in data analytics

Assignment
Lead a team of 4–5 developers for a SaaS product in AWS that provides scalable REST APIs for personal data. The team was also responsible for maintaining an additional service providing APIs for corporate data.

Impact
Marcus led the technical work within the team, taking responsibility for system architecture and coordinating with other teams and leaders across the company. Under his leadership, integrations with Nordic government data sources were further developed. He also took ownership of the team’s technical documentation required to become an approved data provider for the Norwegian national registry (Folkeregistret).

Marcus participated in the entire development lifecycle, from requirements gathering to delivered product, and contributed to technical customer interviews to continuously improve the service based on customer needs.

Assignment
In a team of 4–5 developers, enhance a SaaS product in AWS that provides scalable REST APIs for personal data.

Impact
Marcus played a leading role in the system’s architecture, focusing on improving performance and functionality. He actively worked to improve the quality of search results for queries such as people and addresses using Information Retrieval (IR) techniques, including stemming.

Using a dedicated information retrieval test suite, system accuracy was measured with an F-score, allowing continuous adjustment and optimization of the algorithms for better search results.

Marcus also emphasized system quality and robustness. He contributed to ensuring that the microservices could handle high load through code optimization, improved database indexing for faster lookups, and the implementation of rate limiting and circuit breakers to protect the system against overloads and DoS attacks.

2020 - 2021

Developer

Large American company in data analytics

Assignment
Develop a platform for container-based deployment tailored to the company’s systems, where Kubernetes was not allowed for certain use cases.

Impact
Marcus, together with 2–3 developers, built a platform enabling containerized deployment on a set of on-premises servers. A CLI was developed that allowed the desired system state to be defined and submitted via configuration files, after which applications were automatically deployed according to the specifications.

Marcus was also responsible for documentation and for training both developers and operations staff on how the platform worked and how to use it effectively.

Technologies
Java, REST, Docker, Kubernetes, Helm, etcd, Kafka, Yaml, JSON, GitLab, Bitbucket, TeamCity

2019 - 2020

Lead Developer

Leading US-based stock exchange services provider

Assignment
Migrate a trading system to run in a cloud environment.

Impact
Marcus adapted the system to be compatible with cloud deployment as microservices and ensured that the services could be configured as needed. He also conducted training sessions for staff on cloud services and how the cloud installation worked, as this was the company’s first cloud-based system. As part of the project, Marcus also set up much of the required cloud infrastructure to successfully complete the migration.

Technologies
Java, REST, Docker, Kubernetes, Helm, Kafka, Yaml, JSON, AWS, SQL

2019 - 2019

Lead Developer

Leading US-based stock exchange services provider

Assignment
Together with a team of three developers, develop a core platform for Java and C++ to be used across all company applications for monitoring, command execution, logging, and configuration management.

Impact
Marcus helped establish agile practices with a strong focus on quality through Scrum and thorough code reviews. He developed platform functionality and made it available for both C++ and Java applications according to stakeholder requirements.

Automated component tests were created to simulate an example application running on the platform, enabling continuous verification of functionality within a CI/CD pipeline. Marcus was also actively involved in collaboration with stakeholders and sister teams in other countries, including the USA, India, and Lithuania, and participated in a bootcamp in New York aimed at coordinating and integrating the teams’ systems.

Technologies
Java, C++, Kafka, Docker, Kubernetes, Helm, Yaml, JSON, REST, Redis

2017 - 2019

Developer

Leading US-based stock exchange services provider

2017 - 2017

Developer

Global leader in music streaming

Assignment
Personalize the album page for users at the world’s largest music streaming service, taking into account that different users have different preferences.

Impact
Marcus developed software to personalize the album page using Information Retrieval (IR) methods combined with statistical models. The solution dynamically adjusted the order of page categories — such as popular tracks, artist biography, and related content — to present them in the way most relevant to each individual user.

The algorithm was based on the user’s past behavior in relation to the interests of other users. By calculating a TF-IDF–based statistical measure, the system was able to rank and prioritize categories individually for each user.

Technologies
Java, Cassandra, GCP, BigQuery, REST

Assignment
Explore potential applications of blockchain technology within the transportation industry.

Impact
The company’s trucks collected large volumes of environmental and road-condition data. Marcus investigated how the company could fairly share this data with competitors while ensuring that parties were financially compensated based on the amount of data they contributed.

As part of this work, Marcus co-developed a patented algorithm to enable atomic exchanges of data for assets on a blockchain — Blockchain Two-Phase Contract.

He also developed an Android application demonstrating how payments could be made using a custom digital currency secured via the Bitcoin blockchain, using so-called Colored Coins.

Technologies
Java, Android, Blockchain

2017- 2017

Developer

Major Swedish truck manufacturer

Assignment
Example code for the company’s integrated development environment (IDE) for embedded systems.

Impact
Marcus developed and ported example code for multiple architectures to demonstrate how the company’s IDE can be used for embedded systems development. The example code, available directly within the IDE, provides a user-friendly starting point, making it easy for customers to quickly get started with their development.

Technologies
C/C++

2016 - 2016

Developer

Tooling provider for embedded systems