diff --git a/README.md b/README.md
index 3edc7aff..5e4d15f5 100644
--- a/README.md
+++ b/README.md
@@ -129,11 +129,16 @@ $ make stop language=node
 
 #### Pre-requisites
 
-- The language you intend to use is installed on your machine and available at your command line.
-  This repo should generally work with active LTS versions of each language such as node >= 14,
-  python >= 3.8, ruby >= 2.6, etc.
+- The backend language you intend to use is installed on your machine and available at your command line.
+  This repo should generally work with the latest active LTS versions of each language, and language version
+  files such as `.nvmrc`, `.python-version`, etc are included in each directory for use with popular version management utilities.
+    - Node 14, npm 6
+    - Python 3.8
+    - Ruby 2.7
+    - Java 16
+    - Go 1.16
+- [Node 14](https://nodejs.org/en/download/) with the default `npm` version 6 (for running the frontend).
 - Your environment variables populated in `.env`
-- [npm](https://www.npmjs.com/get-npm)
 - If using Windows, a command line utility capable of running basic Unix shell commands
 
 #### 1. Running the backend
diff --git a/frontend/.npmrc b/frontend/.npmrc
index 19dd2939..8684cd60 100644
--- a/frontend/.npmrc
+++ b/frontend/.npmrc
@@ -1 +1,2 @@
 registry=https://registry.npmjs.com
+engine-strict=true
diff --git a/frontend/Dockerfile b/frontend/Dockerfile
index 5ee1bd0c..4e61e809 100644
--- a/frontend/Dockerfile
+++ b/frontend/Dockerfile
@@ -1,5 +1,5 @@
 # pull official base image
-FROM node:lts-alpine
+FROM node:14-alpine
 
 # set working directory
 WORKDIR /app
diff --git a/frontend/package.json b/frontend/package.json
index 90d69fa8..6087ed01 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -1,5 +1,9 @@
 {
   "name": "plaid_react_quickstart",
+  "engines": {
+    "node": "^14",
+    "npm": "^6"
+  },
   "version": "0.1.0",
   "dependencies": {
     "@testing-library/jest-dom": "^5.11.4",
diff --git a/go/Dockerfile b/go/Dockerfile
index 1edca997..0f5bb222 100644
--- a/go/Dockerfile
+++ b/go/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:1.12 AS build
+FROM golang:1.16 AS build
 
 WORKDIR /opt/src
 COPY . .
diff --git a/node/.npmrc b/node/.npmrc
index 19dd2939..8684cd60 100644
--- a/node/.npmrc
+++ b/node/.npmrc
@@ -1 +1,2 @@
 registry=https://registry.npmjs.com
+engine-strict=true
diff --git a/node/Dockerfile b/node/Dockerfile
index c114dc88..71061dc4 100644
--- a/node/Dockerfile
+++ b/node/Dockerfile
@@ -1,4 +1,4 @@
-FROM node:alpine
+FROM node:14-alpine
 
 WORKDIR /opt/app
 RUN chown -R node:node /opt/app
@@ -11,4 +11,4 @@ COPY --chown=node:node ./node/index.js ./
 
 EXPOSE 8000
 ENTRYPOINT ["node"]
-CMD ["index.js"]
\ No newline at end of file
+CMD ["index.js"]
diff --git a/node/package.json b/node/package.json
index dd33cdab..39ac3665 100644
--- a/node/package.json
+++ b/node/package.json
@@ -1,5 +1,9 @@
 {
   "name": "plaid-node-walkthrough",
+  "engines": {
+    "node": "^14",
+    "npm": "^6"
+  },
   "version": "0.1.0",
   "description": "A sample app and accompanying walkthrough for the Plaid API.",
   "main": "index.js",
diff --git a/python/.python-version b/python/.python-version
new file mode 100644
index 00000000..d20cc2bf
--- /dev/null
+++ b/python/.python-version
@@ -0,0 +1 @@
+3.8.10
diff --git a/python/Dockerfile b/python/Dockerfile
index 54cded1b..97a55338 100644
--- a/python/Dockerfile
+++ b/python/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:alpine
+FROM python:3.8-alpine
 
 WORKDIR /opt/app
 COPY . .
diff --git a/ruby/Dockerfile b/ruby/Dockerfile
index be66ebb6..abd99f4a 100644
--- a/ruby/Dockerfile
+++ b/ruby/Dockerfile
@@ -1,4 +1,4 @@
-FROM ruby:2-alpine
+FROM ruby:2.7-alpine
 
 WORKDIR /opt/app
 COPY . .
diff --git a/ruby/Gemfile b/ruby/Gemfile
index 9d0ef17d..31eac17e 100644
--- a/ruby/Gemfile
+++ b/ruby/Gemfile
@@ -1,4 +1,5 @@
 source 'https://rubygems.org'
+ruby '~> 2.7'
 
 gem 'sinatra'