- Twitter (2011) from Ruby to Scala
- Urban Airship (2011) from MongoDB to PostgreSQL
- Mixpanel (2011) from Erlang to Python
- LinkedIn (2012) from Ruby to NodeJS
- MoovWeb (2012) from ? to Go
- NTP Pool (2012) from Perl to Go
- DLGoogle (2012) from C++ to Go
- Bitly (2012) from Python/C to Go
- SoundCloud (2012) from Ruby to Go
- SmartyStreets (2012) from .NET to Go
- Toggl (2012) from Ruby to Go
- Shareaholic (2012) from MongoDB to Riak
- DigiDoc (2012) from MongoDB to PostgreSQL
- Etsy (2012) from MongoDB to MySQL
- TekPub (2012) from MongoDB to PostgreSQL
- TargeterApp (2012) from NodeJS to Ruby
- PayPal (2013) from Java to NodeJS
- Koding (2013) from NodeJS to Go
- Iron.io (2013) from Ruby to Go
- Zalora (2013) from PHP to Go
- TimeHop (2013) from Ruby to Go
- Canonical Juju (2013) from Python to Go
- Instill (2014) from AngularDart to Polymer
- Workia (2014) from ActionScript to Dart
- TrustWave (2014) from ActionScript/Flex to Dart
- Facebook Chat (2014) from Erlang to C++
- Grab (2014) from Ruby/NodeJS to Go
- Auth0 (2015) from Apache Kafka to ZeroMQ
- Pinterest (2015) from Java to Elixir
- President University (2015) from PHP/MySQL to Go/PostgreSQL
- UserLike (2015) from MySQL and MongoDB to PostgreSQL
- Olery (2015) from MongoDB to PostgreSQL
- CrowdStrike (2015) from Scala to Go
- DockYard (2015) from Ruby to Elixir
- CrowdStrike (2016) from Scala to Go
- Tokopedia (2016) from Perl to Go
- Uber (2016) from PostgreSQL to MySQL
- Uber (2016) from NodeJS to Go and Java
- Uber (2016) from Python to Go
- Digg (2016) from NodeJS to Go
- Google AdWords (2016) from GWT to Angular Dart
- Bleacher Report (2017) from Ruby to Elixir
- UpGuard (2017) from JRuby to Go
- Movio (2017) from Scala to Go
- Discord (2017) from MongoDB to Cassandra
- Uber (2017) Riak/Solr to Cassandra
- Swat.io (2017) from MySQL to PostgreSQL
- Poki (2017) from PHP to Go
- Stream (2017) from Python to Go
- Baidu (2017) from MySQL to CockroachDB
- Boxzilla (2017) from PHP to Go
- Shippable (2017) from MongoDB to PostgreSQL
- GeekyAnts (2017) from ReactNative to Google Flutter (confirmed)
- AppTree (2018) from Java/Kotlin/ObjC/Swift to Dart
- SendGrid (2018) from Perl/Python to Go
- Bukalapak (2018) from Ruby/MySQL to Go/MongoDB/ElasticSearch
- Centrifugo (2018) from Python to Go
- The Guardian (2018) from MongoDB to PostgreSQL
- AppsFlyer (2019) from Clojure to Go
- Deliveroo (2019) from Ruby to Rust
- Amazon (2019) from OracleDB to Aurora Postgres and DynamoDB
- Two Fintech Giants (2019) from OracleDB to CockroachDB
- Comcast (2019) from Cassandra to ScyllaDB
- Codism (2019) from Python to Go
- Discord (2020) from Go to Rust
- HSBC (2020) from DB2 to MongoDB
- Unnamed US Wireless Carrier (2020) from Oracle to PostgreSQL
- ListenBrainz (2020) from InfluxDB to TimescaleDB
- Dropbox (2020) from Nginx to Envoy
- Repustate (2020) from Python to Go
- SimilarWeb (2020) from NodeJS to Go
- PayPal (2020) from C++ to Go
- KhanAcademy (2021) from Python to Go
- ownCloud (2021) from PHP to Go
- Percona (2021) from Prometheus to VictoriaMetrics
- Aluma (2021) from C# to Go
So many migrating to Go ^^. If it's not about migration, there's a lot more here that apparently choose Go (interviews, from X to Go, and also more here).
NOTE: this list will be no longer updated, you can see the lastest changes on github repo so anyone can contribute/update.
If you found any more news like this, paste the link on the comment, I'll gladly add them on the list.