Toss tech stack
Toss builds mostly with SQL, Python, Kotlin, Java. Its stack also includes Kubernetes, Apache Kafka, ClickHouse, Redis. LLM is named in 24 of the 78 job postings Toss published in the last 12 months (31%). Counted by Alion from the job postings of Toss, updated Sep 28, 2026.
What programming languages does Toss use?
SQL is named in 24% of job postings at Toss, followed by Python (23%), Kotlin (9%), Java (8%).
Show all (10)
What frameworks and libraries does Toss use?
Hadoop is named in 6% of job postings at Toss, followed by Flink (4%), FastAPI (3%), PoC Library (3%).
Hadoop
5 6%
Flink
3 4%
FastAPI
2 3%
PyTorch
2 3%
Scikit-learn
2 3%
Spring Boot
2 3%
Spring Cloud
2 3%
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What databases does Toss use?
ClickHouse is named in 8% of job postings at Toss, followed by Redis (8%), ElasticSearch (6%), MySQL (5%).
ClickHouse
6 8%
Redis
6 8%
ElasticSearch
5 6%
MySQL
4 5%
Milvus
3 4%
Neo4j
2 3%
Snowflake
2 3%
StarRocks
2 3%
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What cloud and platforms does Toss use?
Kubernetes is named in 15% of job postings at Toss, followed by Apache Kafka (14%), Grafana (9%), Spark (9%).
Kubernetes
12 15%
Apache Kafka
11 14%
Grafana
7 9%
Spark
7 9%
Figma
4 5%
AWS
3 4%
GitHub
3 4%
GitHub Actions
3 4%
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What developer tools does Toss use?
Prometheus is named in 10% of job postings at Toss, followed by dbt (6%), ArgoCD (5%), Git (5%).
Prometheus
8 10%
dbt
5 6%
ArgoCD
4 5%
Git
4 5%
Claude Code
3 4%
Thanos
3 4%
WebRTC
3 4%
Adobe After Effects
2 3%
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What AI and ML technologies does Toss use?
LLM is named in 31% of job postings at Toss, followed by LoRA (1%), VLM (1%), PEFT (1%).
Which engineering practices does Toss ask for?
Red Teaming is named in 12% of job postings at Toss, followed by Platform Engineering (10%), RAG (9%), AI Agents (8%).
Platform Engineering
8 10%
RAG
7 9%
AI Agents
6 8%
CI/CD
6 8%
Function Calling
2 3%
SLI/SLO/SLA
2 3%
Show all (36)
What other technologies does Toss use?
Swift Concurrency is named in 1% of job postings at Toss.
Swift Concurrency
1 1%
What does each Toss team work with?
The technologies each team's postings require most often, with the number of postings that require them.
AI/ML
15 postingsData Science
11 postingsDevOps
5 postingsHow does your stack fit Toss?
How is the Toss stack changing?
Read from the dates of the postings themselves: a technology is new when the first posting that names it appeared in the last six months, rising or falling when its share of postings moved between the last two quarters.
How modern is the Toss stack?
Toss scores 81 out of 100 (Cutting-edge). The score averages how current each technology in the stack is and adds weight for AI adoption. AI technologies in the stack: 4; legacy ones: 0.
Companies with a stack like Toss
Questions about the Toss tech stack
What programming languages does Toss use?
The languages named in Toss job postings are SQL (24%), Python (23%), Kotlin (9%), Java (8%), TypeScript (4%), as a share of the 78 postings of the last 12 months.
Does Toss use Hadoop?
Yes. Hadoop is named in 5 of 78 job postings (6%) and required in 5 of them.
What cloud and platforms does Toss use?
The cloud and platforms named in Toss job postings are Kubernetes (12), Apache Kafka (11), Grafana (7) (postings in brackets).
What skills do you need for a AI/ML job at Toss?
AI/ML postings at Toss most often require LLM (10), vLLM (3), ElasticSearch (2), Grafana (2), out of 15 postings in the last 12 months.
Is the Toss tech stack changing?
Yes. Speech Recognition, Text-to-Speech, WebSockets, gRPC first appeared in Toss job postings in the last six months.
How modern is the Toss tech stack?
Toss scores 81 out of 100 (Cutting-edge). The score averages how current each technology in the stack is and adds weight for AI adoption. AI technologies in the stack: 4; legacy ones: 0.
How does Alion know the Toss tech stack?
Alion reads every job posting Toss publishes and tags the technologies each one names. The figures on this page count the 78 postings of the last 12 months and were updated on Sep 28, 2026.
Method and citation
Alion reads every job posting the company publishes and tags the technologies each one names. Shares count the postings of the last 12 months, open and closed; the company's own products are counted apart. How we count
Alion, "Toss tech stack: 166 technologies from 78 job postings", as of Sep 28, 2026. https://alion.io/company/viva-republica/technologies